Media identification systems utilize a variety of techniques to identify media (e.g., television (TV) programs, radio programs, advertisements, commentary, audio/video content, movies, commercials, advertisements, web pages, and/or surveys, etc.). In some media identification systems, a code is inserted into the audio and/or video of a media program. The code is later detected at one or more monitoring sites when the media program is presented. An information payload of a code inserted into media can include unique media identification information, source identification information, time of broadcast information, and/or any other identifying information.
Media identification systems may additionally or alternatively generate signatures at one or more monitoring sites from some aspect of media (e.g., the audio and/or the video). A signature is a representation of a characteristic of the media (e.g., the audio and/or the video) that uniquely or semi-uniquely identifies the media or a part thereof. For example, a signature may be computed by analyzing blocks of audio samples for their spectral energy distribution and determining a signature that characterizes the energy distribution of selected frequency bands of the blocks of audio samples. Signatures generated from media to be identified at a monitoring site are compared against a reference database of signatures previously generated from known media to identify the media.
Monitoring sites include locations such as, households, stores, places of business and/or any other public and/or private facilities where media exposure and/or consumption of media on a media presentation device is monitored. For example, at a monitoring site, a code from audio and/or video is captured and/or a signature is generated. The collected code and/or generated signature may then be analyzed and/or sent to a central data collection facility for analysis. In some systems, the central data collection facility or another network component may also send secondary media (e.g., secondary media associated with the monitored media) to the monitoring site for presentation on a media presentation device. For example, the secondary media may be an advertisement associated with a product displayed in the monitored media.